- Joined
- Dec 20, 2012
- Messages
- 9,422
Most if not all small LATHES will never part off a piece of metal. My reason for saying this they lack the strength to keep the parting blade from flexing. First the tool rest moves , compound flexes , the cross slide moves the ways even torque over. If you ever expect to part you will need the tool blocked up from the ways with a roller bearing to support the blades movement up to the point of just touching the piece to be cut . Rigid as possible no flexing at all then the blade still will flex and may break. I'm in the design stage of making a rotating saw blade mounted to the tool post , like a grinder , only mounted in a qctp with air fitting . My thinking with the lathe turning and blade turning no flex of any amount should make much difference. I'm letting the cat out of the bag but I'm sure it works.
With all due respect, I have to disagree, Silverbullet. I have an Emco 11" lathe that parts everything I turn with a HSS P-type blade or an Aloris GTN3 inserted carbide blade. My little Sherline can part anything that will fit in the lathe using a P1-N blade mounted upside down in a rear mounted parting tool post. In fact, the Sherline will part mild steel at 1200-1500 rpm and will cut 303 stainless washers 0.010" thick without any issues at all.
A sharp blade mounted perpendicular to the work with the tip at center height will part easily on most lathes, small or big. I think the biggest problem for most guys is that what they think is center height is not really center height; a bit high and it won't cut; a bit low and it digs in a snaps the blade. A positive feed is also important.